1. Field of the Invention:
The present invention is directed to using the left and right angled flighting on rasp bars of a transverse threshing cylinder to direct a harvested crop into an axial separator.
2. Description of the Prior Art:
In processing a harvested crop, the grain is separated from straw and chaff and deposited into a holding tank. With conventional combines the harvested crop is directed to a transversely mounted threshing cylinder and concave which threshes the crop separating the grain from straw. The residue is then directed to a beater further separating the grain from straw. The straw residue is then passed over oscillating apertured straw walkers which direct the straw out of the back of the combine while allowing additional grain to fall through the apertures. Grain and chaff falling from the threshing concave and straw walkers is then directed to a cleaning shoe for separating the chaff from the grain. A blower assembly is used in this final step to blow the lighter chaff away from the heavier grain.
In an axial flow combine, the grain is directed to a cylindrical tube housing a rotor. The harvested crop is threshed and separated in the cylindrical tube with the grain and chaff falling therefrom in a manner similar to the conventional combine. Case International of Racine, Wisconsin currently markets and manufactures a axial flow combine having a single rotor. Ford New Holland of New Holland, Pennsylvania currently markets and manufactures an axial flow combine having a pair of rotors mounted side-by-side.
A hybrid machine having a transverse threshing cylinder and a pair axial separating units is disclosed by the assignee of the present invention in U.S. Pat. No. 4,739,773. In this patent the harvested and threshed crop material is directed to the inlet of the axial separator units by an overshot beater. Cooperating guide vanes assist in directing the crop material to the inlets of the two axial separator units. This patent also discloses using specially shaped beaters to direct the flow of crop material from the threshing cylinder to the two axial separators units.
U.S. Pat. Nos. 3,034,513 and 3,256,887 disclose threshing cylinders having transverse rasp bars that are provided with angled flighting. Each rasp bar has left angled flighting and right angled flighting.